JPS60501426A - Metal mold for tricurved hydrophilic contact lens and method for producing optical surface of the mold - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Tricurved hydrophilic contact lens and method for molding the same The invention relates to contact lenses, particularly Unique tricurved structure designed to correct myopia This invention relates to a spherical hydrophilic contact lens. This lens was specially manufactured Can be easily molded or cast directly into the desired shape using a replica mold. Ru. We will also discuss lens molding methods.

In a preferred aspect of the invention, the hydrophilic A contact lens is cast and its central zone is substantially thinner than the periphery of the lens. stomach. Contact lenses designed to correct nearsightedness refract light, The center of the lens must be thinner than the periphery for proper optical correction . The difference in thickness increases as the bending power of the lens increases.

The bending power (dioptres) varies from 0 to -20.0, but generally most of the It ranges from 0 to -6 for the myopic population. Therefore, the thickness at the center is 0.03 to 0.5 It will be in the range of 5mm. Therefore, use the thinnest hydrophilic contact lenses possible. design, i.e. with a center thickness of e.g. 0.04 mm, This maximizes the penetration of oxygen through the lens to the wearer's cornea, thus reducing contact It is desirable to promote the health of the patient's cornea while wearing lenses. . These contact lenses provide patient comfort for longer periods of time than lenses of standard thickness. It will be possible to install it.

Hydrophilic contact lenses are not rigid, but rather generally contain a substantial amount of A three-dimensional chilimer of one or more types that traps water (one-third or more) It has a network structure. Due to the above centering and thickness requirements, general designs and The manufacturing method was found to be inadequate. The ultra-thin hydrophilic structure produced in this way Contact lenses are extremely thin and soft, so their light bending power is particularly low. It was found that insertion and removal were extremely difficult. especially the lens patient convenience and hydrophilicity in the case of low bending powers where the surfaces of the Integrity and at least partial stability are required for the acceptance of contact lenses It is.

The unique bicurved design lens of this invention provides the necessary strength at the center of the lens periphery. This gives the lens extra mass, which improves the necessary integrity and handling required for the lens. give the desired characteristics. This lens is durable enough to be handled and handled on the patient's hands or fingers. It is relatively easy to insert and remove sushi. Another advantage is that the bicurved design Zine increases both the tensile and tear strength of the lens, thus increasing its longevity. It has the effect of prolonging life and reducing accidents caused by torn lenses.

The dicurved lens of the present invention can be easily manufactured by casting or molding. The casting method is Reduces costly machining and polishing of lenses when manufacturing tact lenses. Also known as shi, or to exclude. US patent! 4.121896 specification (T According to the method W described in , H, 7F 1.), the optical molding surface is also Two complementary replica male and female molds are injection molded with a plastic composition in the master mold pair. Manufactured by Next, arrange these plastic molds vertically, Used for molding contact lenses. Preferably, one of the molding surfaces is provided with the resulting resin. Provides a flexible peripheral rim that defines the outer edge of the lens. Load the component into the female mold piece or section. Complementary male part or male part into female part This positions the flexible rim on the molding surface on the opposite side. During molding The lens-forming material contracts and bends the flexible rim, usually inward, thereby The two types of molded pieces move toward each other. When one molding cycle is completed The mold is separated and the resulting contact lens is cleaned and perhaps removed from the lens rim. It is taken out in a ready-to-use state for immediate washing, with the exception of puff polishing.

The tricurved five-sided lens of the present invention is generally spherical, but may also be manufactured into a toric structure. . Optionally the lens can be truncated to ensure positional stability when placed on the cornea. and/or may have a prismatic ballast. molded Toric contact lenses are described in U.S. Pat. No. 4,208,365 (R, J, Fiber) and pending U.S. Patent Application No. 199,780 (Elink) ・Nople) has been criticized. Truncated contact lenses are issued P CT application WO 32104221 (Hardt, Magton and Nople, 19. Published December 9, 1982). Thermoplastic materials (general VC poly Propylene molds are available in U.S. Pat. No. 4.1211396, U.S. Pat. '36 No. 4 and No. 4,208,365.

The object of the invention is that extra mass is provided centrally around the periphery of the lun, thereby making it more flexible. Gives the lens the necessary Wlit' and desirable handling characteristics, while reducing the tensile strength of the lens. Another object of the present invention is to increase both strength and tear strength from 0 to -20 diopters. , preferably 0 to -8 diopters, preferably 0 to -6 diopters, The center part is extremely thin, and it has all the handling characteristics of a general dicurved lens. It is an object of the present invention to provide a bicurved spherical water-based contact lens which has the following characteristics.

The purpose of the pond of the present invention is to be very thin in the central part of the optical band, i.e. about 0. 03 to about 005, which increases oxygen permeation and transmission. An object of the present invention is to provide a hydrophilic contact lens.

An object of the present invention is to provide a method for directly casting dicurved lenses. , lenses cast in this way require little or no hand finishing. I don't need it.

These and other objects of the invention will be apparent from the following more detailed description and accompanying drawings. It will become clear.

Summary of the invention The present invention is a bicurved contact lens, that is, an optical zone A□ at the center of the lens. It also has three distinct spherical radii that define three distinct regions containing the central spherical surface of action. About things. The optical band is the area of the lens that exhibits various desired capabilities; The radius of the sphere that defines the area remains constant for the first time as the lens capacity changes. . The typical diameter of this zone, measured in the dry (unhydrated) state, is approximately 8.50+++m.

The second band or portion A2G is primarily annular, adjacent to and concentric with the optical band, and is optically It has a thickness that increases monotonically outward in the radial direction from the school zone. This band is an optical band. This second band also has a flat radius and similarly varies depending on the lens's ability (C). Although the optics of the second band 6 necessarily change in conjunction with changes in the optical band itself, The purpose of the area is primarily supportive. The spherical radius of this second band is shown below. The thickness of the lens is determined by a unique molding process, so it is decisive. child It is possible to create various lenses by flattening or steepening the spherical radius of the metal master. This means that the center thickness should be obtained. Furthermore, this band also depends on the optical characteristics of the lamp. in this area of the lens (i.e. band) without adversely affecting fit. Strengthens the lens by providing additional cerimer mass.

The third zone A3 has a taper in which the thickness decreases outward from the optical zone, and is outside the lens. Define the side diameter. The radius of curvature defining this zone is substantially constant. this is It can be moved vertically while separated, which changes the depth value in the direction of separation. it is conceivable that. Various types of lenses can be created by making the spherical radius steeper or flatter. Get the thickness. Please compare Figure 3 with Figure 4.

In a preferred form, the cast contact lens of the present invention has an inner radius of 0.5 to 1 0.8mm, schistosome i12.5~], 8.0mm5 and center thickness 0.03~1 ．． 0mm, preferably about 0.03-0.05mm, ideally about 0.04mm It is hemispherical/L. The material of the lens is ethylene glycol dimethacrylate and It is a hydrophilic serimer of bridged 2-hydroxoethyl methacrylate. Use and (This lens is 09% chlorinated) l) Equilibrated with rum solution. In this state, the composition is 62% by weight of hydrophilic polymer and 38% by weight of water. %. Human cornea: When placed on the human cornea, the hydrated lens forms a spherical or toric lens. It acts as a corrective refractive medium to compensate for the refractive error of the lens. The above hydrophilic J+) - General 7 special table Sho GO-501426 (4) It has a refractive index of 143 and visible light transmission of 97% or more.

FIG. 5 shows the manufacture of contact lens molds with three distinct spherical radii according to the present invention. The mathematical calculations required to do this are shown. Figures 7.8 and 8A manufacture metal master molds. The method for doing so will be explained later.

Creation of metal master mold for optical band: A two-split metal mold 2o for manufacturing a replica lens mold is shown in Figure 5. It was manufactured using an optical radius lathe in the following manner with reference to the distance. Precise quality light Including performing the necessary mathematical calculations in advance to obtain the bicurved metal master mold for academic use. A series of mold-making operations involving precision step-by-step machining, lamp finishing, and polishing are performed. Ta. The insert 22 defining the optical surface 24 is made of bar material (Colt Industries) Manufactured from a steel blank (254 +++ m) obtained from C3M414 stainless steel (machined to an approximate size of 16 mm and then cut to a length of 19 mm).

Next, the tapered hole 26 is bored and reamed to create a blank face. I got one of these. This tapered hole accepts the lumen of the Brown & 7 Yarp #2. I had it. Since all other surfaces, including the optical surface, originate from this point, this hole must be accurately must be placed. For this operation, a 10-inch Hardinge Norle A machine lathe was used.

Using the same machine, the blank produced in this way was processed into a Braun Ant 9 for adjustment. ・Light with 6 pieces placed on a sharp taper and rotated with a concentricity of 0.005mm The blank was turned to a finished diameter of 1540±001 mm. Then a 5° step was cut into a blank to have a length of 65 mm and a main diameter of 12.80 mm.

Cut a +5° taper with a -1° tapered step into the front of the optical mold. , its main dimensions are 1258 fighting tenacity and 12.38mm, and the radius is 0.50mm. 050 steps were left on the front shoulder. Similarly, mold the optical sleeve 5 to a depth of 14.0 mm in the tapered bore to hold it in place within the 28 A 716-24 thread was cut.

Optical sleeve 28 is made of A76 tool steel and hardened to 56-58RC. Ta. , the front part was bored to a diameter of 15.40mm and a depth of 198゜mm, and here An optical mold 22 was placed at the. A plastic replica cast from this metal mold. 5° angle at the front for mold removal and stated wall thickness . Strains in the plastic mold that may impair the parameters and quality of the optical surface This angle should be adjusted to 15mm along with a diameter of 19.50mm to avoid this occurring inside the product. Must be ground concentrically with the inner diameter of 40mm, V, 1° The operations above to create the optical surface 24 determine the focus, optical, brightness and brightness of the lens. This is important because it controls the growth and thickness. Robertnon radius lathe with proper tool height and and center (C) and then adjust this for pre-tapered hole cutting. Radius lathe head with stock spindle R-Brown Anton A pre-prepared mold blank was fixed to the Yabe tapered taper.

First, to establish a reference starting point, the radius A1 is set on the lathe dial ten, and the lathe touched the center of the mold blank and cut it.

The headstock was set at 30 mm. This procedure provided a reference starting point. . The radius A□ determines the degree of correction or power of the resulting lens. Next, look at armpit 5 After calculating the various halves shown in the headstock, I set it on the itinerary. Set radius A2, then until proper optical band 24 is obtained Insert 22 was cut by adjusting the memory stop. optical band Visually inspected with a tool making microscope (accuracy within 0.005 degrees). Then radius A 1 on the lathe dial again, place the lathe head at the proper stroke again, and set the corresponding The A□ band was cut into a blank and blended with A2 at appropriate coordinates. Finally the radius The lathe was set to radius A3 (radius A3 is smaller than A□ and A2, and this As it is cut into the blank, it overcomes both, so the memory stop unnecessary). However, the radius A3 is the same as A1. By calculating A2 stroke and center thickness I can't stand it.

The machining of the bicurved metal master mold 20 is a complex, precise, and long-term process that requires rigor. It's a manipulation. Sag of the bicurved radius (all 5aCO1 are harmonized with the sag of the basis curve) and must match, thereby establishing a predetermined nominal center thickness. For example, 004 mm) is obtained. Radius A2 is thicker than radius A1 (so half When cutting diameter AI, be careful not to scrape the entire mold blank. Must. The radius A2 is important because it determines the nominal center thickness of the lens. Ru.

Grinding bicurved molds is also an operation that requires care and precision.

Optical radius with tight focus, perfect radial dimension, and 3 curved surfaces 10 are all blendable with each other at the A/A2 and A2/A3 contact points. This is because a surface finish must be provided. Similarly, the machined mold is Levins lens surface pattern with Brown and 7-yard arbor for adjustment. I put it on the board.

Various grades of abrasive compounds and wooden dowels were used. Separate for each radius Using dowels, each dowel was cut with the required radius. First, for flat 3 polishing A wooden dowel containing the compound was used to sand the precise radius. The radius is A1, A2 was polished, followed by A3. Vibrate a wooden dowel of appropriate dimensions above. While doing so, I rotated the mold around the center. Various vibrations for the corresponding medium diameter to be polished Using dynamic angle, dispersion and wood diameter - all tool marks removed and tightened When focus is obtained, the polishing at this point is considered complete.

The final polishing was first 51, then! Contains 61/2 diamond polishing compound. It was performed using a soaked Fusaka-covered sponge pad.

From this (C), the two-curved surface has a tight focus and shine, and there are no scratches. were all removed from the steel surface.

The optical surface of the lens shown in Figures 3 and 4 and the lathe stroke shown in Figure 5 The n values for are as follows, diameter (1) sphere radius (1) Drawing A1 + A2 + A3 A1 A2 A33 s5o 10.50 11 ．． 98 7.45 s, oo 7.044 8.50 10.50], ],, 98 7,45 8,50 7.045 8.50 10.50 1. ], ]9 　V'''　v　v(1) Measured in the soft, unhydrated state.

11 Special Feature Sho GO-50142G (5) (2) Change according to desired optical ability. Movement.

Creating a base curved metal master mold: The base curved metal master mold 30 includes two structural units, a base curve insert 32 and a button. Consists of 34 shells. Both parts are made of 411 stainless steel as described above. same The bar was turned from 25 mm to 130 mm using this equipment. On the Hardinge lathe Set the installation of compound 9 to 5°, and set the 5° taper from 13.0mm. It was turned to a diameter of 952mm. At the same time, a straight section with a diameter of 9.52 mm and a length of 10.0 m Machined to +++. With the same compound setting, diameter 13.0ho From ++ to diameter 952 mm, an internal taper angle of 10 mm in length is machined to Bunonyu 34. Machined. The insert 32 and the bushing 34 have precision fittings that fully engage each other. It should have a taper. For tapered fit, steel insert 3 The 0.07mm edge on 2 allows the plastic layer with the desired parameters to be Arrange them against each other so that a plica mold is obtained. Harp 4fufu 10 inch lathe speed Using a taper with a needle, fix the base curved bushing here and adjust the outer diameter to The appropriate dimensions were 17.22mmKmm. This ensures overall concentricity Ru.

Next, place the base curved insert 32 on the spindle of the Levin radius lathe, and The pared insert is machined to a concentricity of 0.005 mm, where the basal Machined the radius of the curved surface. The appropriate depth in the strip direction was determined using the following formula.

The above formula is the recognized sag height 2 for optical molds and base curved molds. This is the string that represents the diameter of the school band, and this is for band A1 in Figure 1. is 1/2 of 8.50 mm, or 425 mm, for the sum of the diameters of bands A1 and A2. That is 14 of 10.50 mm, or 525 cities.

Using the same dial stroke calculation method used to manufacture the mold that defines the optical surface. 9, the same radius as the required base radius and the same radius cut into the base steel. Diameter 15.9 with chi/maw holes on the back side of the wood that harmonize with the single shaft/mitsu board of the wood. A 0mm wooden lamp was attached to a Levin puff board. Attach the mold to the wooden lamp and It was supported by wooden nails on the floorboard. All tool scratches are removed by the approximately 30° oscillating motion. Both the wooden lamp and the steel mold were rotated until a smooth optical surface was obtained.

The edge was then placed in the mold insert using a piece of wood with a concave radius of 684 mm. child The wood was mounted on a puff board with a base curved insert 32. Support h and h with your hands. and was multiplied by rotating tree 1. This operation is performed by the 007mm Eno) 36. I kept repeating it until it was broken. Edge 36 (shown in more detail in Figure 8A) Define the flexible peripheral rim of the plastic replica mold manufactured from scratch. Final research The polishing was done in the same manner as the optical curve 38 mold. These two completed constituent units 32 and 34, and insert insert 1-; 1. O-32 set screw 40 It was supported in place.

The diameter of the optical mold 20 with a 5° angle provides adequate space and avoids excess material. 0.4.0 mm thicker than the diameter of the base curved mold 30 in order to allow the mer to escape. It was. The 1° inverse taper improves the base curve by preventing Zoris l in the lens. plastic 3 Acts as a guide 9 for the parts.

Plastic replicas made of thermoplastics (e.g. ethylene) The molds were manufactured using standard injection molding techniques from finished metal starter molds. plus The tick replica type is disclosed in the above-mentioned US Pat. No. 4.1.2], No. 896, No. 4.208.364 and U.S. Pat. No. 4.208.365. manufactured by the method. Those descriptions are quoted here for reference.

FIG. 1) and female type 4 are shown as a form of the Nararo Silastic Replica type. I got a male type The child 2 includes a substantially cylindrical support segment 6 with a flexible rim at its lower end. What is 8 wearing? The cylindrical support segment 6 is hollow as shown. It may also be a solid agglomerate. Flexible rim 8 supports support segment 6 form a ring around the outer edge of The support segment 6 is around the bottom of the support segment 6. is closed by the molding surface 12 attached to the molded contact lens, and defines the base curved surface of the molded contact lens. do. The molding surface 120 curvature is selected to match the optical requirements of the lens to be manufactured. It will be revealed. The complementary molding surface 180 curvature includes three distinct zones as described above, resulting in Define the optical curved surface of the Lero lens. The optical band is generally spherical, aspherical, or both. Any combination of persons is acceptable. Female molding to define the back curved surface of the final lens Surface 16 is generally a spherical surface, but may also be a toric surface, an aspheric surface, or a combination of both. good,.

The female type gadoko 4 (which may be hard or soft) has a cylindrical shape in a stand 16 provided around it. support segment [or wall 14, and circle 14 An optical shaping surface 18 is included on the inside of the cylindrical support segment 14 . female type The inner diameter of the support segment 14 is slightly larger than the inner diameter of the male support segment 6. Easy to insert.

Other forms of plastic replica molds can be made by injection from the metal molds shown in Figures 7 and 8. The molded version is shown in FIGS. 9 and 9A. FIG. 9A shows an enlargement of the flexible peripheral rim 8. It's a big picture.

The method of the present invention uses truncated noftoplasty contact lenses (i.e., in hydrated form). hydrogels) K (these are not the preferred products) ). Hard or rigid contact lenses as well as soft hydrophobic contact lenses. Also includes

A novel method allows contact lenses to be cast directly from the desired lens forming material. Can be slightly finished or puffed around the edges of the lens without the need for polishing the optical surfaces; Only polishing is required; overall processing is more labor intensive than prior art methods It is advantageous over prior art methods in that it is much lower. Most knot lenses At 5K, the lens was washed with water to remove catalyst residue and unreacted monomers, and then Equilibrate in aqueous or saline solution to obtain its final dimensions.

By implementing the preferred aspects of the present invention, a wide range of Various contact astragalus exhibiting optical bending power can be economically advantageously obtained.

Practice of the present invention provides three distinct bands or regions and a contiguous A molded three-view contact lens with a smooth outer circumference has been obtained as a new product. It will be done. The optical power of the lens is 0 to -20 diopters, preferably O to -8 diopters. diopters, preferably 0 to -6 diopters. Preferably the new article is 90 gel, especially containing a major amount of 2-human 90/ethyl methacrylate (HEMA). It is a hydrophilic polymer.

One of the molding surfaces, usually the male girdle, is provided with a flexible integral peripheral rim. is preferred, which means that when practicing the preferred aspects of the invention, the resultant lens is It will define the outer edge or edge. The lens-forming material does not shrink during the molding operation. (preferably during the addition or condensation reaction), the flexible rim is usually attached to the circumferential axis of the mold. and bend it inward, which brings the two molds closer to each other. Flexible rim structure Regarding construction, materials, etc., see U.S. Patent No. 4.121. , No. 896 and No. 4,208 , No. 365.

These descriptions are cited in their entirety by reference.

Three-view contact lenses made according to the present invention include non-substituted and fluorine-substituted lenses. flexible hydrophobic materials as exemplified by polyethylene, soricone elastomers, and You can also use a leaf lens.

Alternatively, this type of contact lens is based on the so-called hydrophilic lenses with a three-dimensional structure. For example, JIJ mer of 2-hydroxoethyl methacrylate, various hydrophilic It may also be a collagen thawed product. Hydrophilic Astragalus is water-insoluble and water-swellable. and take their final dimensions when immersed in water or saline solution. The resulting water-swollen lens It would be appropriate to call them hydrogel lenses.

Rimmers, Pre-48 Rimmers or Vulcanizable Mixtures Particularly Useful in the Practice of the Invention hydrophobic acrylic acid esters, especially acrylic acid lower alkyl esters ( ・Carbon atom 6 with 1 to 5 alkyl moieties acrylic acid or methyl methacrylate, acrylic acid or ethyl methacrylate, acrylic acid or n-propyl methacrylate, Impropyl acrylic acid or methacrylate, acrylic acid or methacrylate Inobutyl acid, n-butyl acrylate or methacrylate, or these Includes various mixtures of monomers. To increase dimensional stability and warpage resistance The monomer or monomer mixture described above may be added with a small amount of di- or Cross-linking of the polymer matrix as the polymerization progresses by further mixing with different types of You can also make it happen. This type of bifunctional or polyfunctional type includes: Contains things. Divinylbenzene, ethylene glycol diacrylate or is methacrylate, professional level licor diacrylate or methacrylate and acrylic acid esters or methacrylic acid esters of the following polyols: Le: triethanolamine, glycerin, pentaerythritol, phthalate Coal, diethylene glycol, triethylene glycol, tetraethylene glycol Cole, mannitol, norbitol, etc. Other cross-linked monomers include N, N- Notylene-bis-acrylamide or methacrylamide, sulfonated divinyl Includes rubenzene and divinyl sulfone.

The above monomers or mixtures thereof are added to the filtrate solution or "casting lump" that is formed. Linear, unless the viscosity becomes so large that it is difficult to remove the bubbles from it. =p Can be further mixed with IJ ma type.

Other monomeric materials suitable for making lenses according to the invention include three-dimensional crosslinked networks. Structure-forming hydrophilic monomer mixtures, such as U.S. Pat. No. 3.822.089 This is what is stated in the specification of the No. Examples of hydrophilic monomers include: Let's go. One hydroxyl group that can be esterified with acrylic acid or methacrylic acid and a few Water-soluble monoesters with alcohols having at least one additional hydroxyl group, e.g. Mono- and polyalkylene glycol monoesters of methacrylic acid and acrylic acid Stell, Tatoeba Ethylene Glycol Monomethacrylate, Ethylene Glycoso Monoacrylate, diethylene glycol monomethacrylate, diethylene glycol Cole monoacrylate, fluoropylene gellicol monomethacrylate, dipropylene such as lene glycol monoacrylate; N-alkyl substituted and N,N-dial Kill-substituted acrylamides and methacrylamides, such as N-methylacrylamide Amide 9, N, N-dimethylacrylamide, N-methylmethacrylamide, N , N-dimethylmethacrylamide, etc.; N-vinylpyrrolidone; alkyl-substituted N -vinylpyrrolibin, such as methyl-substituted N-vinylpyrrolidone; methacrylic acid gly/zyl; gly/zyl acrylate; and others known in the art. Similarly, there is Vulcanizable silicone oils or elastomers are used.

Preferably, the number of alkyl moieties and alkylene moieties in each of the above groups is 4. Contains up to carbon atoms.

For mixtures of hydrophilic monomers, a three-dimensional crosslinked network structure is formed. It is preferable that For this purpose, small amounts of crosslinking monomers, such as hydrophobic Consideration of cross-linking methods (e.g. radiation method) for crylic esters and others; Please explain 18 It is preferable to use something similar.

Preferred monomer mixtures include at least one alkylene glyco of methacrylic acid. monoesters, especially ethylene glycol monomethacrylate, and less and one crosslinking monomer, such as alkylene glycol diethyl methacrylic acid. esters, especially ethylene glycol dimethacrylate. This kind of mixture is another polymerizable monomer, such as N-vinyl chloride/methyl methacrylate. , acrylamide, N-methacrylamide, diethylene glycol monomethacrylate Rates and other of the foregoing may be present, if desired in minor amounts.

The polymerization reaction can be carried out in bulk or using an inert solvent. in a suitable solvent is water; organic solvents such as water-soluble lower aliphatic alcohols and polyhydric alcohols; such as glycols, glycerin, dioxane, etc.; and mixtures thereof. Contains compounds. Generally, when a solvent is used, this is a sub-volume of the reaction medium, i.e. 50 Weight gain also accounts for a small amount.

Polymerization of the monomer mixture is usually carried out using free radical polymerization catalysts of the type customary for vinyl polymerization. Use it. This type of catalyst includes organic peroxides, percarbonates, and water peroxide. and inorganic substances, such as ammonium difluoroxosulfate, sodium Contains potassium. Polymerization using this type of catalyst depends on the desired polymerization rate. It can be carried out at ambient temperature, i.e. from about 20°C to about 120°C. You can do it.

Polymerization occurs between monomers or prepolymer mixtures at elevated temperatures or by radiation (skin (2) It is also carried out under the action of X-rays or other known radioactive materials.

/ In the case of silicone elastomers, vulcanization appears to occur via a free radical curing mechanism; In the case of two-component so-called RTV compounds, vulcanization occurs by substitution or condensation reactions. It seems that it will be difficult. Regarding lens forming fees useful in the manufacture of contact lenses. Further patent specifications include, for example, U.S. Reissued Patent No. 27401; No. 3.63a524; No. 1699.089; No. 1700.761; No. 182 No. 2089; No. 4.121.896; No. 4.208.365 and No. 4.2 No. 21984 is detailed in each specification. These are quoted here in their entirety for reference.

Lens casting: Polypropylene is produced using injection molding equipment from the metal molds described and explained above. Two molds were manufactured. These two complementary types are determined by predetermined parameters. One mold is optically curved plastic (female mold) and the other is base curved plastic. (male type). 2-hydroxyethyl methacrylate (976%) in the female type, Ethylene glycol dimethacrylate (14%) and bis(4-t-butylsilyl) Liquid monomer mixture consisting of (1%) 45ml11' of compound was loaded.

After loading, place the male mold into the female mold as shown in Figure 9, and insert the loaded mold into the female mold. The liquid monomer was polymerized by placing it in a furnace at a temperature of 125° C. for 30 minutes. From mt furnace It was removed and allowed to cool, then the finished lens was removed from the mold and inspected for dimensions.

All lenses manufactured from certain plastic molds that are injection molded from steel molds are They had the same dimensions. A brief description of these dimensional drawings FIG. 1 shows a bicurved contact showing three distinct zones or regions in accordance with the present invention. There is a plan view of the lens.

FIG. 2 is a cross-sectional view of the lens of FIG. 1 taken along line 2--2.

Figures 3 and 4 show different lens thicknesses and corresponding bands. Figure 2 is a cross-sectional view of a lens according to the invention showing the variation of the spherical radius.

Figure 5 shows the change in the radius of the sphere and the radius lathe between the three renal protrusion centers along a common axis. This is an illustration of the calculation of the stroke.

FIG. 6 is a cross-sectional view of the replica lens mold in the open position.

Figure 7 is a cross-sectional view of a metal master mold for forming the optical surface of a plastic replica mold. It is.

Figure 8 shows a cross section of a metallic seed mold for forming the base curved surface of a plastic replica mold. It is a front view.

Figure 8A shows the template of Figure 8 defining the peripheral rim of the male portion of the plastic replica mold. This is an enlarged flash of Super.

Figure 9 shows another form of plastic injection molded from the metal molds of Figures 7 and 8. It is a sectional view of a tick replica type.

FIG. 9A is an enlarged view of the peripheral rim of the plastic male portion of FIG. 9;

FIG.4 F I G, 7 F I G, 8 Procedural amendment (formality) 1.Display of the incident PCT, /US84100742 2. Name of the invention Bicurved hydrophilic contact lens and its molding method 3, person performing correction Relationship to the incident: Applicant address Name: International Hytron Corporation 4. Agent Address: Room 206, Shin-Otemachi Building, 2-2-1 Hitemachi, Chiyoda-ku, Tokyo 7. Contents of correction As shown in the attached sheet (note that there are no changes to the contents of each document in (3) and (4)) international search report

Claims (1)

[Claims] 1. Optical zone with upper and lower surfaces; a first support band that is contiguous with and concentric with the optical zone and has an upper surface and a lower surface; Consisting of a first radius of curvature in which the lower surfaces of the optical zone, the first support band and the second support band have a common radius; and a second center of curvature, the upper surface of the optical zone being larger than the first radius of curvature. The radius of curvature and the first radius of curvature are such that the upper surface of the first support band is closer to the second radius of curvature. also has a large third radius of curvature and a second center of curvature, and the upper surface of the second support band It has a fourth radius of curvature and a third center of curvature smaller than the radius of curvature, and and a third center of curvature are located along a common axis across the optical zone; is closest to the optical band, and a second center of curvature is the hydrogel coating furthest from the optical band. contact lenses. 2. The lens according to claim 1, wherein the lens curvature is 40 to -20 diopters. Drogel contact lenses. 3. The lens according to claim 2, wherein the optical power of the lens is 0 to -8 diopters. Human 90 gel contact lens C4 The light bending power of the lens is O~-6 diopters A human 90 gel contact lens according to claim 3. 5. A claim in which the optical band has a nominal center thickness of approximately 0.04 mm ± 0.02 m. Human 90 gel contact lens according to item 1. 6 The lens is made of acrylic monomer, N-alkylacrylamide), N, N-di alkylacrylamide 9, N-alkylmethacrylamide), N,N-dial a polymer selected from the group consisting of methyl methacrylamide and N-vinyl 0 lolidone; A hydrogel contact lens according to claim 1, which is made from a rimer. . 7 Human 90 gel is a polymer of 2-hydroxyethyl methacrylate, A human 90 gel contact lens according to item 1. 8. Central spherical surface with one edge; a first annular portion that is concentric with the spherical surface and has an inner edge in contact with an edge of the spherical surface, and an outer edge; and the thickness of the first annular portion increases monotonically in the radial direction from the inner edge to the outer edge. portion; a second annular portion having an inner edge concentric with the first annular portion and touching an outer edge of the first annular portion; an annular portion, the thickness of the $2 annular portion being the inner edge of the second annular portion (the thickness of the first annular portion); the thickness is the same as that of the outer edge) to the outer edge of the second annular portion. a little bit A bicurved contact lens consisting of 9 Predetermined method to form the first optical surface of the desired contact lens. a first mold portion having a principal axis including an optical molding surface having a curvature; predetermined to form the desired second optical surface of the contact lens. A second mold part with a principal axis including an optical molding surface with curvature. Karanaro is a thermoplastic mold for manufacturing bicurved contact lenses. The optical forming surfaces of these together form a central spherical surface with one edge; 23 a first annular portion that is concentric with the spherical surface and has an inner edge in contact with an edge of the spherical surface, and an outer edge; The stiffness of the first annular portion increases monotonically in the radial direction from the inner edge to the outer edge. part; and the inner edge which is concentric with the first annular part and touches the base of the first annular part; a second annular portion having a thickness that is equal to or smaller than the inner edge of the second annular portion (the first annular portion); (having a thickness equal to the thickness of the outer edge of the annular section) to the outer edge of the second annular section in the radial direction. Monotonically decreasing part A mold that surrounds the area that defines the three-sided contact lens. 10. Predetermined to form the first optical surface of the desired contact lens. a first mold portion having a principal axis including an optical molding surface having a curved curvature; predetermined to form the desired second optical surface of the contact lens. a second mold section having a principal axis including an optical molding surface having a curvature; A soft material is provided around the edge of one of these optical molding surfaces and is integrally attached thereto. A soft rim part that is common to the main axis of the mold part to which it is attached. , and the rim portion has an axis of A bicurved contact lens consisting of a material that can move relative to each other between the two optical faces. A mold made of thermoplastic material for the manufacture of optical lenses with an optical molding surface and a flexible lip. The area between the two edges is a central spherical surface with one edge; a first annular portion that is concentric with the spherical surface and has an inner edge in contact with an edge of the spherical surface, and an outer edge; minutes, and the thickness of the first annular portion is equal to or less than 24 minutes from the inner edge. ) monotonically increasing in the radial direction toward the outer edge; concentric with the first annular portion; a second annular portion having an inner edge in contact with an outer edge of the first annular portion, the thickness of the second annular portion being from the inner edge of the second annular portion (which has the same thickness as the outer edge of the first annular portion) A monotonically decreasing portion in the radial direction toward the outer edge of the second annular portion A type that defines a bicurved contact lens consisting of: Claim 10, wherein at least one of the 11° optical forming surfaces has a spherical structure. Types listed in section. 12. Claim 10, wherein the rim portion is attached to a mold portion having a convex shaped surface. The type described in. 13° The first mold portion has a substantially convex molding surface and the second mold portion has a substantially concave molding surface. 13. A mold according to claim 12, having a molding surface. 14. The integrated rim portion faces inward in the direction of the axis of the molding surface to which it is integrally attached. 11. The mold according to claim 10, which has a bent end. 15. (a) A mixture consisting of vulcanizable or polymerizable components is included in claim 10. ('b) the first mold part and the second mold part; The main axes of the mold parts coincide with each other and the flexible rim parts are molded on opposite sides. The mold is closed by arranging them one another in a manner located around the surface; The mixture is then closed as a whole by maintaining pressure between these molding surfaces and the flexible rim portion. and (c) convert the resulting closed quantitative system into a desired mixture of under activating conditions for a period sufficient to cause some degree of vulcanization or polymerization; The soft rim portion is bent in a generally uniform manner relative to the axis of the forming surface, thereby bringing the mold parts close to each other during vulcanization or polymerization; and (d) Take out the product with the shape of the obtained tricurved contact lens The manufacturing method of three-curved contact lenses consists of several steps. 16. Claim 15, which includes applying external pressure to the mold during the polymerization step. Method. 17. The mixture contains acrylic monomer, N-alkylacrylamide V,N,N-di Alkylacrylamide, N-alkylmethacrylamide, N,N-dialkyl Contains at least one polymerizable monomer selected from the group consisting of methacrylamide. The method according to claim 15. 18. Claim 15, wherein the mixture consists of 2-hydroxyethyl methacrylate The method described in section. 19. As a molded part central spherical surface with one edge; a first annular portion having an inner edge concentric with the spherical surface and in contact with an edge of the spherical surface, and a row edge; ; and a second annular portion having an inner edge concentric with the first annular portion and touching an outer edge of the first annular portion; minutes A metal master mold for injection molding plastic replica molds. Engraving (no changes to the content)